Evaluation of deformation parameters for deformable image registration-based ventilation imaging using an air-ventilating non-rigid phantom
Evaluation of deformation parameters for deformable image registration-based ventilation imaging using an air-ventilating non-rigid phantom
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DOI：
10.1016/j.ejmp.2018.05.016
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发表时间：
2018-06-01
影响因子：
3.4
通讯作者：
Nishio, Teiji
中科院分区：
文献类型：
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作者：
Miyakawa, Shin;Tachibana, Hidenobu;Nishio, Teiji
目的：本研究的目的是评估不同的变形图像配准（XNUMX）参数的开源NiftyReg包在其应用程序中的DIR为基础的通气imaging.Methods：两个三维（3D）计算机断层扫描（CT）扫描的非刚性的空气通气体模采集在峰值呼气和峰值吸气，氙气（XNUMX）气体被用作基于空气的造影剂。我们比较了四组不同的参数，包括一组两步变形和三组四步变形。对于空间准确性，计算了16个标志的目标配准误差（TRE）。对于通气成像精度，使用雅可比行列式（JD）度量生成基于DIR的通气图像，随后测量两个呼气和吸气CT图像之间的亨氏单位（HU）值变化。计算JD指标与HU值变化之间的相关系数。平均TRE值为4.5 ± 4.7 mm（最大值，12.3 mm），1.47 +/- 0.71 mm（最大值，2.6 mm），1.56 +/- 0.70 mm对于两步变形和三个四步变形，分别为1.53 +/- 0.66 mm（最大值，2.8 mm）和1.53 +/- 0.66 mm（最大值，2.5 mm）。四步变形（R =-0.71、-0.65、-0.61）的相关系数比两步变形（R = -0.40）的相关系数更高。结论：基于DIR的通气成像的准确性可能因不同的呼吸机参数设置而异，即使空间准确性可能是可容忍的并且在指南范围内。我们发现四步NiftyReg工具的参数设置足以显示模拟肺通气功能。
Purpose: This study aimed to evaluate different deformable image registration (DIR) parameters for the open-source NiftyReg package in its application to DIR-based ventilation imaging.Methods: Two three-dimensional (3D)-computed tomography (CT) scans of a non-rigid air-ventilating phantom were acquired at peak exhalation and peak inhalation, with xenon (Xe) gas being used as an air-based contrast agent. We compared four different sets of DIR parameters, including one set with two-step deformation and three sets with four-step deformation. For spatial accuracy, the target registration error (TRE) was calculated for 16 landmarks. For ventilation imaging accuracy, DIR-based ventilation images were generated using Jacobian determinant (JD) metrics, and changes in Hounsfield unit (HU) values between the two exhalation and inhalation CT images were subsequently measured. The correlation coefficients between the JD metrics and changes in HU values were calculated.Results: The mean TRE values were 4.5 +/- 4.7 mm (maximum, 12.3 mm), 1.47 +/- 0.71 mm (maximum, 2.6 mm), 1.56 +/- 0.70 mm (maximum, 2.8 mm), and 1.53 +/- 0.66 mm (maximum, 2.5 mm) for the two-step deformation and three four-step deformations, respectively. The four-step deformations (R = -0.71, -0.65, and -0.61) showed stronger correlation coefficients than the two-step deformation (R = -0.40).Conclusions: The accuracy of DIR-based ventilation imaging may vary with different DIR parameter settings, even though spatial accuracy may be tolerable and within guidelines. We found adequate parameter settings for four-step NiftyReg DIR for visualization of simulated pulmonary ventilation function.